The present invention relates to a tool holding apparatus in an NC lathe.
In the conventional tool holding apparatuses of this kind, the center of a polygonal tool post is rotatably fixed on a vertical shaft installed on a saddle, a tool is held on every side of said tool post and the tool post is clamped on said vertical shaft at the time of working. Accordingly, they have been attended with a drawback that, as often as one tool is switched over to another, it is necessary to follow the procedure that the tool post should be turned after releasing it from clamping on the vertical shaft and thereafter be clamped on the vertical shaft again, thereby wasting time in switchover of tools.